The generator matrix

 1  1  1  1  1  1  1  1  X  0  X X^3+X^2  1  X X^3  X X^2  1
 0  X X^3+X^2 X^2+X X^3 X^3+X^2+X X^2 X^3+X X^2+X  X X^3+X  X  0 X^3+X^2+X  X  X  X X^3+X^2

generates a code of length 18 over Z2[X]/(X^4) who´s minimum homogenous weight is 17.

Homogenous weight enumerator: w(x)=1x^0+8x^17+108x^18+8x^19+1x^20+1x^24+1x^28

The gray image is a linear code over GF(2) with n=144, k=7 and d=68.
As d=71 is an upper bound for linear (144,7,2)-codes, this code is optimal over Z2[X]/(X^4) for dimension 7.
This code was found by Heurico 1.16 in 1.05e-007 seconds.